But both Democratic candidates for the U.S. Senate have the edge over former Gov. Linda Lingle, according to the latest Civil Beat Poll.

Former Congressman Ed Case appears to be running stronger against the Republican Lingle than sitting Congresswoman Mazie Hirono, the poll found.

The automated telephone survey of 1,358 likely voters found Case has a 13 percentage point margin over Lingle, 46 percent to 33 percent. Hirono has a 7 percentage point margin, 46 percent to 39 percent. In each case, roughly 20 percent of likely voters said they were either undecided or would pick another candidate.

The poll was conducted on January 18 and 19, and has a margin of error of +/- 2.7 percent.

Case and Hirono, both lawyers, are facing off in the Aug. 11 Democratic primary. Neither has won a statewide race at the top of a ticket before, and Hirono has already been defeated once by Lingle, in the 2002 governor’s race.

In a traditionally Democratic state, the presence of the two-term Republican governor in the contest has put the seat into play and thrust Hawaii’s contest onto the national stage. Control of the Senate is at stake and Hawaii is one of the states where Republicans could make gains. Lingle announced later than her potential opponents, but last week exhibited the strength of her candidacy when she released fundraising figures showing she has already dramatically surpassed their totals. That news came after the poll was taken.

The most recent previous independent poll of this race came just days after Lingle entered the fray in October. Public Policy Polling found Hirono besting Lingle, 48 percent to 42 percent, and Lingle essentially tied with Case, with the Republican at 45 percent and the Democrat at 43 percent. The margin of error was +/- 4.1 percent. Since then, Case has had a much more visible campaign than Hirono.

The Civil Beat Poll highlights the potential importance of the presidential race for Hawaii’s U.S. Senate battle. In 2008, the presence of Hawaii-born Barack Obama helped boost turnout. Obama, according to the Civil Beat poll, retains his immense popularity here, with nearly two-thirds of likely voters still approving of his performance in office, much higher than his rating nationally.

Lingle makes a point of arguing for party diversity in Congress, so that no matter which party controls the Senate Hawaii will be well represented. Today, all four representatives of the state in Washington, D.C., are Democrats. She also encourages people to think of each race separately, that it’s OK to support the president — and her.

The more Democrats the president can help attract to the polls, the better for either Democratic Senate candidate. The poll found that in a contest between Hirono and Lingle, of those who strongly approve of the president, 75 percent would support the Democrat and just 13 percent the Republican. Of those who approve of the president somewhat, 56 percent back Hirono and 27 percent choose Lingle. But when it comes to those who disapprove of Obama, the numbers are overwhelmingly for Lingle. Of those who disapprove strongly, 93 percent opt for Lingle, as do 71 percent of those who disapprove somewhat.

In a contest between Case and Lingle, 70 percent of those who approve strongly of Obama would vote vote for him, versus 14 percent for her. For those who approve somewhat, the percentages are 57 and 18. But those who disapprove of the president are not quite as negative about Case as they are about Hirono, with Lingle picking up 82 percent of those who disapprove strongly and 58 percent of those who disapprove somewhat.

The same trend appears to hold true for party affiliation.

In a contest between Case and Lingle, 69 percent of Democrats back Case to 13 percent for Lingle, with 18 percent undecided or saying they wouldn’t vote for either candidate. Independents split 48 percent for Case and 34 percent for Lingle, with 75 percent of GOP voters backing Lingle and 14 percent choosing Case.

In a showdown between Lingle and Hirono, 68 percent of Democrats would vote for Hirono and 18 percent for Lingle. Hirono picks up 45 percent of independents, with Lingle getting 42 percent. Lingle again dominates among Republicans, with 80 percent to 13 percent for Hirono.

While the poll indicates Case is in a stronger position versus Lingle today, an analysis of what primary voters who back Hirono and Case will do in the general election shows more voters will switch to Lingle if Case wins the primary.

If Case beats Hirono, the poll shows that he would retain 58 percent of his supporters but that 40 percent would shift to Lingle. If Hirono beats Case, 86 percent of her supporters will stick with her, while just 12 percent would switch to Lingle.

Only 27 percent of Case’s supporters would stick with Hirono, while 59 percent would switch to Lingle. In contrast, more than half of Hirono’s supporters, 53 percent, would vote for Case. Also potentially of concern to Case if he were to win the primary is that 23 percent of Hirono’s supporters say they wouldn’t vote for either Case or Lingle in the general. Just 9 percent of Case’s supporters wouldn’t vote in a Hirono versus Lingle election.

What the poll reinforces is the conventional wisdom that Case does better than Hirono among independents and Republicans. Case positions himself as a centrist, a moderate in his party, much the way Lingle is doing in her own party. Hirono is on the progressive end of her own party, with a strong liberal voting record.

Lingle gets a lower percentage of support from independents in a contest against Case, 34 percent, than she does against Hirono, 42 percent.

Of course, the poll is just a snapshot of the opinion of likely voters at the time it was taken, roughly nine months before the general election. Much will happen in the campaign that could affect the outcome, especially with outside independent groups pouring money into Hawaii to sway voters to one side or the other. Hawaii voters can expect to see a heated battle between Aug. 11 and Nov. 6.

Among the other findings of the poll:

Hirono vs. Lingle

Hirono does better than the former governor with women, 49 percent to 39 percent. They’re essentially even with men.

Hirono dominates Lingle on the neighbor islands. Even Maui, where Lingle served as mayor before running for governor, opts for Hirono, 61 percent to 27 percent.

The neighbor island results are reflected in the congressional district results. Hirono does not appear to have as strong a presence on Oahu. She leads in the 2nd Congressional District, which she represents in Congress, 51 percent to 38 percent. But in the 1st Congressional District, they’re even, 43 percent for Hirono and 42 percent for Lingle.

Case vs. Lingle

Case beats Lingle among both men and women, with a 48 percent to 37 percent edge among men and a 49 percent to 32 percent lead among women.

Case leads Lingle in every county, including Oahu, where he gets 48 percent of the vote versus 36 percent for Lingle.

The margin for Case is essentially the same in both congressional districts. He leads in the 1st 48 percent to 34 percent, and in the 2nd he is on top 49 percent to 35 percent.

The challenge for Case will be whether he can emerge from a Democratic primary to take on Lingle. Hirono has the backing of the party establishment and union supporters. She also has more money. The Civil Beat poll found the race is a dead heat at this point, but that a higher turnout will be critical for Case because Democrats are more likely to align themselves with Hirono while independents and Republicans are more drawn to Case.

What may help Lingle is that she can build her war chest for the general election while Case and Hirono duke it out in the primary, potentially exposing the flaws in each candidate and weakening the primary victor’s ability to overcome a proven statewide winner.